Quantifying Species Diversity of Streetside Trees in our Cities

Article Figures & Data

Table 1.

An example of SDI calculation for streetside tree populations.

The original data were published by Jim (11). ∑ Nj is the total of streetside trees and ∑ Nj·(∑ Nj - 1) = 1084 x (1084 - 1) = 1173972. SDI =Σ Nj · (∑ Nj -1) / ∑ Nj (Nj - 1) = 1173972 / 196440 = 6.0.

Table 2.

Species diversity index (SDI) of streetside tree popuylations in 21 cities and towns. SDI was calculated according to the formula (2).

City or town	SDI	Original data from
United Kingdom
Northamptonshire	4.4	(1)
Avon County	4.5	(1)
Churchyards in Gwynedd, Wales	5.8	(5)
Lambeth Borough, London	6.0	(13)
Manchester City	6.9	(19)
District of Arfon,Gwynedd, Wales	7.3	(7)
Norfolk	8.4	(1)

Unites States
Reed Keppler Park trees	5.0	(8)
Syracuse, NY	6.5	(15)
New Orleans, LA	7.6	(18)
Urban Springfield, MA	9.2	(4)
Prince Georges, MD	10.0	(21)
40 towns in Iowa	11.5	(20)
Urban Amherst, MA	11.7	(4)
Wicomico, MD	13.6	(21)
Northwestern University campus, IL	14.9	(12)
Two Urbana, IL neighborhoods	15.9	(3)
Anne Arundel, MD	20.1	(21)

Other countries
Longyan, Fujian, China	6.0	(11)
Athens, Greece	11.4	(14)
Hong Kong	12.7	(10)